The aircraft belly fairing stores equipment and systems located between the wing and the fuselage such as air conditioning equipment, fuel systems and the landing gear. The size and location of the landing gear bay is the main constraint for the ventral fairing design.
The main objective of the ventral fairing aerodynamic design is to minimize the negative interferences between the wing, the fuselage and the ventral fairing, in order to achieve the least aerodynamic drag penalty possible and to improve the airflow adherence conditions around the wing surface.
From a structural point of view, known belly fairings are formed by a rigid skin and an inner reinforcing structure comprising longerons and frames arranged in perpendicular directions. The skin is usually formed by several panels (particularly composite honeycomb panels) bolted or fastened to the longerons and frames.
This invention is addressed to an improvement of known belly fairings and similar external parts of aircraft in weight and drag reduction as well as in assembly and maintainability using inflatable structures.
The use of inflatable structures in aircraft is not new and some proposals for deployable structures and/or structures able to changes of shape are known, such as U.S. Pat. No. 5,681,010 that discloses a deployable, inflatable aerodynamic control structure for aerospace vehicles which has a desired non-circular or non-cylindrical cross-section, U.S. Pat. No. 7,185,851 B2 that discloses a wing that includes an array of inflatable chambers with generally circular cross-sections or US 2005/0151007 A1 that discloses an inflatable, rigidizable wing for a terrestrial or planetary flying vehicle that can be deployed from an initially packed condition to assume its functional shape by means of an inflation gas.
However inflatable structures will be used in the present invention in a very different way to these proposals.